Insulation piercing electrical connection



May 16, 1967 J. E. MARLEY ETAL INSULATION PIERCING ELECTRICAL CONNECTION Filed Feb. 15, 1965 5 S heets-Sheet 1 May 16, 1967 J. E. MARLEY ETAL 3,320,354

INSULATION PIERCING ELECTRICAL CONNECTION Filed Feb. 15, 1965 3 Sheets-Sheet. 2

May 16, 196 J. E. MARLEY ETAL 3,320,354

INSULATION PIERCING ELECTRICAL CONNECTION Filed Feb. 15, 1965 3 Sheets-Sheet 5 United States Patent 3,32li,354 INSULATION PIERCING ELECTRICAL CONNECTION James Earl Marley, Middletown, Lincoln Edwin Roberts, Harrisburg, and John Ambrose Ward, Carlisle, Pa.,

assignors to AMP Incorporated, Harrisburg, Pa.

Filed Feb. 15, 1965, Ser. No. 432,621 7 Claims. (Cl. 174-84) This application is a continuation-in-part of our copending application, Ser. No. 391,087, filed Aug. 21, 1964, for Electrical Connection, now abandoned.

This invention relates to electrical connections of the type in which a generally channel-shaped connector is crimped onto an insulated wire and in which means are provided in the connector to penetrate the insulation of the wire and make electrical contact with the conducting core thereof.

An object of the invention is to provide an improved connector which is adapted to be crimped onto an insulated wire to form an electrical connection therewith. A further object is to provide an improved splice connector. A further object is to provide an insulation penetrating type electrical connector including means for forming an insulating sheath in surrounding relationship to the connection when the connector is crimped onto the wire. A still further object is to provide a splice type connector intended for usage in a crimping tool of a type which trims the conductor and positions the conductor within the connector during the crimping operation.

These and other objects of the invention are achieved in one embodiment thereof comprising a butt splice connector for connecting up to four wires with each other. The connector is of generally channel-shaped cross-section comprising a web and upstanding sidewalls. Two pairs of spaced-apart tongues are struck up from the web, each tongue extending transversely across the web and each tongue having a pair of spaced-apart notches extending inwardly from its upper edge for reception of the wires. One pair of tongues is disposed adjacent to one end of the connector and is intended to receive a pair of wires extending from one direction while the remaining pair of tongues is disposed adjacent to the other end of the connector and intended to receive a second pair of wires. The sections of the sidewalls of the connector which are contiguous to, and extend alongside, each pair of tongues are separated from the end sections of the sidewalls and from the center section of the sidewalls by discontinuities in the sidewalls so that these contiguous sidewall sections can be crimped independently of the end and center sections. These contiguous sidewall sections have preformed marginal portions which are directed inwardly and into overlying relationship with respect to the web. These preformed portions of the contiguous sidewall sections thus form flanges which are bendable into overlying relationship with respect to the tongues and which function to force the conductors into the notches in the tongues during crimping. In accordance with one embodiment of the invention, ears are struck inwardly from the sidewalls beneath the above described preformed portions. These ears cooperate with the preformed portions of the sidewalls to assist in forcing the wires into the notches. The end and center sections of the sidewalls are substantially straight and are adapted to be curled inwardly towards each other and downwardly towards the web. In accordance with the preferred embodiment, these end and center sections are initially curled during crimping in a manner such that the individual wires are positioned and centered with respect to the notches in the tongues so that upon subsequent bending of the preformed marginal portions of the contiguous sidewall sections, the wires will be forced 3,320,354 Patented May 16, 1967 downwardly into the notches and the insulation of the wires will be penetrated by the edges of the notches. If desired, a relatively thin film of suitable insulating materials such as Mylar polyethylene terephthalate can be provided on the external surface of the connector. During crimping, the marginal portions of this film are folded inwardly and are clamped between the bent sidewalls of the connector to form a continuous insulating sheath that covers the finished crimped connection.

In the drawing:

FIGURE 1 is a perspective view of an uncrimped splice connector in accordance with a preferred embodiment of the invention;

FIGURE 2 is a perspective view of the connector of FIGURE 1 after crimping;

FIGURE 3 is a longitudinal sectional view taken along the lines 3-3 of FIGURE 2 showing the connector of FIGURE 1 positioned between a die and anvil and showing the relative positions of the parts at the completion of the crimping operation;

FIGURES 4 and 5 are sectional views taken along the lines 44 and 5-5 of FIGURE 1;

FIGURES 6 and 7 are views taken along the lines 66 and 77 of FIGURE 3 and showing the relationship of the crimping dies to the connector after the connector has been crimped onto the wires;

FIGURE 8 is a perspective view of a connector in accordance with an alternative embodiment of the invention;

FIGURE 9 is a transverse cross-sectional view of the connector of FIGURE 8 taken along the lines 99 of FIGURE 8 and showing wires positioned between the connector sidewalls;

FIGURE 10 is a view similar to FIGURE 9 but showing the positions of the parts after crimping; and

FIGURE 11 is an axial cross-sectional view of the connector of FIGURE 8 after crimping.

A preferred form of splice connector 2 in accordance with the invention is particularly intended to be crimped by means of a crimping tool of the general types shown in the co-pending applications of Richard Reem et al., Ser. No. 351,024, filed Mar. 11, 1964 for Method and Apparatus for Making Electrical Connections, and William R. Over, Ser. No. 426,257, filed Jan. 18, 1965, for Crimping Tool. The connector 2 comprises a channel-shaped ferrule-forming member 4 of brass or other conductive metal having an insulating film such as Mylar (polyethylene terephthalate) bonded to its external surface and extending laterally beyond the upper edges of the sidewalls and beyond the ends of the connector. The ferrule-forming member 4 comprises a longitudinally extending web 8 having tongues 10 struck up therefrom which extend transversely across the web and between the sidewalls. In the disclosed embodiment, one pair of the tongues 10 is pro vided adjacent to, but spaced from, each end of the connector. The tongues each have a pair of spaced-apart notches 12 (FIGURE 5) extending inwardly from their upper edges, the width of these notches being slightly less than the diameter of the conducting cores of the wires which are to be connected. The portions 14 of each tongue, which are adjacent to the sidewalls of the connector, have inwardly and downwardly sloping upper edges 16 while the central portion 18 of each tongue has an upper edge portion 22 on one side which slopes relatively gently towards the adjacent notch. The other edge 20 slopes relatively steeply toward the other notch so that the apex formed by the intersection of these two upper edges 20, 22 is off-center with respect to the axis of the ferrule-forming portion of the connector. As explained more fully below, this structure facilitates guiding of the individual wires into the appropriate notches during crimping of the connector onto the wires.

The sidewalls of the ferrule-forming member 4 are divided, by notches 29, to define end sections 28, a center section 30, and intermediate sections 34, which extend alongside, and are contiguous to, each pair of tongues 10. The end sections 28 and the center section 30 extend slightly divergently from the web 8 as shown in FIGURE 4. Each contiguous section 34 comprises an adjacent portion 35 with respect to web 8 and a preformed remote portion 36, 38, 40. This remote portion is separated from the adjacent portion by a longitudinally extending groove 42 which functions as a stress raising device when the remote sidewall portion is bent downwardly towards the web. As explained more fully below, when a downward force is applied to the remote portions of the sidewalls, these remote portions will bend as a unit by virtue of the presence of the groove 42. The inwardly concave crosssection of the remote portions, formed by the inwardly directed section 36 and the reverse bend 38, forms a downwardly concave flange upon crimping which functions to press the wires into the notches 12 and hold them in position.

The insulating film 6 is mounted on the external surface of the ferrule 4 by means of a suitable adhesive and extends laterally beyond the edges of the sidewalls as indicated at 44 to form flaps which are folded inwardly and between the sidewalls during crimping.

The connector 2 is crimped onto the wires by means of a die and anvil set comprising a supporting anvil 56 and a plurality of substantially identical dies 46, 48 mounted on a suitable die holder and contained in a suitable crimping tool which may be of the general type disclosed and claimed in the above-identified Reem et al. application. Thus, each of the dies is provided with convergent forming surfaces 50 which are curved inwardly towards each other as shown at 52 to form a cusp 60. The two spaced-apart dies 48 are so positioned on the die holder that they will move into engagement with the contiguous sidewall portions 34 during crimping while the three spaced-apart dies 46 are so positioned that they will move into engagement with the end and center sidewall portions 28, 30. The dies 46 are in alignment with each other but are disposed on the tool holder with their axes slightly in advance of the dies 48 so that upon movement of the complete die set toward the anvil 56, the end and center dies 46 will come into engagement with the sidewall portions 28, 30 and fold these sidewall portions towards each other and downwardly prior to the commencement of bending of the sidewall portions 34. Preferably, the edges of the die-forming surfaces 50, 52 are beveled as shown at 58 to avoid puncturing or otherwise damaging the insulating film 6. It should be added that the forming surfaces 50 of the dies and the curved surfaces 52 function to curl the marginal portions of the insulating film 6 towards each other and downwardly so that this film will be locked between the sidewalls of the connector as fully described below.

When the connector is crimped with a tool of the type shown in the previously identified Reem et al. application, the tool trims the ends of the wires immediately prior to crimping and positions the trimmed ends in the uncrimped connector. After the wires have been positioned between the sidewalls as shown in FIGURES 4 and 5, the dies 46 will, during their movement towards the anvil 56, curl the end and center portions 30, 28 towards each other so that these ends and center portions of the connector will engage the wires and move them relatively downwardly and against the upper edges 16, 20, 22 of the tongues. During this initial curling of the end and center sidewall portions 28, 30 the wires will be spread apart and each wire will be positioned over a pair of aligned notches in one of the pairs of tongues. The downwardly sloping upper edges 16, 20, 22 of the tongues facilitate this initial positioning of the wires in alignment with the notches 12 and the off-center apex of the central portion 18 of each tongue functions to prevent the wires on one side of the connector from being compressed between the upper edge of this central section 18 and the sidewalls during bending. In other words, during such initial bending or curling of the sidewall portions 28, 30, the wire on the right of FIG- URE S will be moved relatively downwardly against the upper edge 22 of the tongue portion 18 and the upper edge 16 of the tongue portion 14. This wire 26 on the right in FIGURE 5 will then be properly positioned with respect to the right-hand notch in FIGURE 5 and can be moved downwardly into the notch during bending of the contiguous sidewall sections 34. The wire on the left in FIG- URE 5 will similarly be moved against the edge portions 20 and 16 of the central section 18 of the tongue and the left side portion 14 and will be positioned properly with respect to the left-hand notch.

After initial bending of the sidewall portions 28, 30, the dies 48 move into engagement with the contiguous sidewall sections 34. The lower portions 35 of these sidewall sections are bent inwardly and the upper flange portions of these sidewalls are bent downwardly. The bending of the upper sidewall portions downwardly coupled with the further curling of the end and center sidewall portions 28, 30 has the effect of forcing the wires downwardly into the notches 12 at which time the edges of the notches will penetrate the insulation of the wires and establish electrical contact with the conducting cores 24 of the wires. The marginal portions 44 of the insulation on the external surface of the connector will, during this portion of the crimping cycle, be curled inwardly and downwardly. Those parts of the insulation which extend beside the sidewall sections 28, 30 will move against each other and downwardly so that these parts of the insulation will be clamped between the opposed surfaces of the sidewalls as shown in FIGURE 6. This method of clamping of the insulation cannot, however, be attained in the vicinity of the pairs of tongues 10 since the upstanding tongues would prevent downward movement of the marginal sections of the insulation. The insulation in these areas is preferably clamped between the edge portions 22 of the tongues and the flange portion of the adjacent sidewall. The off-center apex of the central section 18 of the tongue functions to guide the edges of the insulation rightwardly in FIGURE 5 when these edges move against the upper edges of the tongues so that the two edges are finally disposed against the edge portions 22 of the tongue and are held thereagainst by the flange and particularly by the curved section 38 of the flange as shown in FIGURE 7.

A salient feature of the invention is that during the crimping operation, the initial curling of the sidewall portions 28, 30 positions the wires in alignment with the notches. The wires are thus lightly stretched across the tops of the tongues and are disposed in the upper portions of the notches prior to bending of the sidewall portion 36, 38, 40. During such bending, the wires are then forced downwardly as explained above.

It should also be noted that during the final portions of the crimping operation, the adjacent sidewall portions 34 may be bent slightly inwardly as is apparent from an inspection of FIGURES 5 and 7. This bending of sidewall portions 34 has the effect of bending the portions 14 of the tongues inwardly at their upper ends thus locking the wires in the notches 12. If this crimping procedure is followed, the wires must be moved into notches 12 before bending of the tongue portions 14 inwardly. This bending step is not essential to the practice of the invention and good results can be obtained if it is not included.

FIGURES 8-11 show an alternative embodiment of the invention that is similar to the embodiment of FIG- URE 1 in most respects but differs therefrom in the provision of ears 60. These ears are struck inwardly from the adjacent portions 35 of the contiguous sidewall sections 34. The length of each of the ears 60 (as measured along the connector axis) is slightly less than the distance between the pairs of tongues and the width of each in such that its upwardly facing surface extends beyond the reversely bent portion 38 of associated preformed sidewall portion 36, 38, 40. The cars 60 thus provide a double thickness of metal between the pairs of tongues 10 for forcing the wires downwardly between the tongues. As best shown in FIGURE 11, the wires are pushed downwardly by a greater amount between the pairs of tongues if the cars 60 are provided than they would be pushed if the ears were not provided. The cars 60 thus constitute stulfers which function to push the wire into the slots 12 of the tongues.

The embodiment of the invention shown in FIGURES 81l has special utility in situations where the diameter of the wire is small relative to the size of the connector. Where the wires are of a relatively large size and/or where they have a relatively thick insulating sheath, the preformed portion 36, 38, 40 of the embodiment of FIG- URE 1 will force the wires into the slots 12 by an adequate amount. If the wires are relatively small and have thin insulating sheaths thereon, a connector in accordance with FIGURE 8 should be used for the reason that the additional downward displacement of the wires which is achieved insures that the wire will be forced into the slots by an adequate amount.

An overall advantage of the invention is that the four wires need be only roughly positioned between the sidewalls of the connector prior to commencement of the crimping operation. When the crimping operation is carried out with a die set of the type shown, the operations of centering the individual wires with respect to the notches 12 in the tongues, of folding the marginal portions of the insulation inwardly and downwardly so that the cross-sections of FIGURE 6 and FIGURE 7 are finally attained, and the forcing of the individual wires into the notches of the tongues are all achieved without further manipulation or positioning of the individual wires by the operator.

This advantage of the disclosed connector is of particular significance where it is desired to make connections rapidly and where operator skill in positioning the wire and in carrying out other manipulative operations cannot be relied upon. When the disclosed form of connector is used with a tool of the type shown in the Reem et al. application or the Over application, it is only necessary for the technician to position the wires in the tool and close the tool handles. Consistent and reproducible results in the finished crimped connections will then be obtained even if the technician fails to exercise care or diligence in properly positioning the wires between the connector.

While the disclosed embodiment of the invention is particularly adapted to make a splice for up to four wires, it will be apparent that the principle of guiding the wires towards the notches and subsequently bending flange portions of the sidewalls over the wires is equally applicable to other types of terminals in connecting devices. For example, a terminal such as a spade or ring-tongue terminal might be provided with a ferrule-forming portion having a pair of struck up tongues 10 and an adjacent ferrule forming similar to the portions 28 of the attached drawing. A terminal of this type could then be crirnped onto an insulated wire without stripping in accordance with the principles of the present invention.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

We claim:

1. An electrical connector intended to be applied to insulated wire, said connector having a generally channel-shaped cross-section comprising a web and upstanding sidewalls, a tongue struck up from said web and extending transversely thereacross, a pair of notches in said tongue disposed on opposite sides of the axis of said connector, said sidewalls each having a marginal portion which is remote from said web and each having an adjacent portion with respect to said web, said marginal portions being separated from said adjacent portions by axially extending weakened zones, said marginal portions of said sidewalls extending from said weakened zones inwardly towards each other thence divergently and away from said web whereby, upon positioning insulated wires between said sidewalls and bending said marginal portions about said weakened zones and into overlying relationship wit-h respect to said web, said wires are forced by said marginal portions into said notches and the edges of said notches penetrate the insulation of said wires to establish electrical contact with the conducting cores of said wires, said marginal portions of said sidewalls forming downwardly concave flanges overlying said webs and functioning to retain said wires in said notches.

2. An electrical connector intended to be applied to an insulated wire, said connector having a generally channel-shaped cross-section comprising a web and upstanding sidewalls, a tongue struck up from said web and extending transversely thereacross, a pair of notches in said tongue disposed on opposite sides of the axis of said connector, a first portion of the upper edge of said tongue adjacent to one of said notches sloping upwardly and away from said one notch, said first portion of said upper edge extending past the longitudinal central plane of said connector, a second portion of said upper edge sloping relatively steeply upwardly from the second one of said notches, said sidewalls each having a marginal portion which is remote from said web and each having an adjacent portion with respect to said web, said marginal portions being separated from said adjacent portions by axially extending weakened zones, said marginal portions being inwardly bendable to form flanges overlying said web, a film of insulating material on the external surface of said connector, the longitudinal marginal portions of said film extending beyond said marginal portions of said sidewalls whereby, upon positioning wires between said sidewalls, bending said marginal portions towards each other, and simultaneously threading said marginal portions of said film between said first upper edge portion of said tongue and the adjacent marginal sidewall portion, said wires are forced into said notches, and said longitudinal marginal portions of said film are clamped between said first upper edge portion of said tongue and said adjacent marginal sidewall portion, the insulation of said wires being penetrated by the edges of said notches thereby to establish electrical contact with the conducting cores of said wires.

3. An electrical connecting device for making a butt connection between wires, said connector having a channel-shaped cross-section comprising a web and upstanding sidewalls, two pairs of tongues struck up from said web, each tongue extending transversely across said web and having a pair of spaced-apart notches on its upper edge for reception of wires, each of said pairs of tongues being disposed adjacent to, but spaced from an end of said connector, the contiguous sections of said sidewalls which extend beside said pairs of tongues being separated from the end sections of said sidewalls and from the center section of said sidewalls by discontinuities in said sidewalls, said contiguous sidewall sections each having a marginal portion which is remote from said web and each having an adjacent portion with respect to said web, said marginal portions being separated from said adjacent portions by axially extending weakened zones, said marginal portions being inwardly bendable to form flanges overlying said web whereby, upon locating wires extending from opposite directions between said sidewalls, and upon curling said end and center sections of said sidewalls towards each other and downwardly towards said web, said wires are moved against said upper edges of said tongues, and upon bending said contiguous sidewall sections into overlying relationship with said web, said wires are forced into said notches in said tongues, the edges of said notches penetrating the insulation of said wires to establish electrical contact therewith.

4. A connecting device as set forth in claim 3 including an ear struck inwardly from each of said adjacent portions, said ears each having a length which is less than the distance betwen the associated pair of tongues and each ear being bendable with its associated marginal portion into overlying relationship with said web, said ears providing a double thickness of metal for forcing said wires into said web.

5. An electrical connector intended to be applied to an insulated wire, said connector having a generally channelshaped cross-section comprising a web and upstanding sidewalls, a pair of tongues struck-up from said web and 20 extending transversely thereacross, a notch in each of said tongues, said sidewalls each having a remote portion which is remote from said web and each having an adjacent portion which is adjacent to said web, said remote portions being bendable relatively inwardly towards each other and towards said web, and wire stuffer means extending inwardly from at least one of said sidewalls, said wire stufier means lying between said tongues whereby, upon positioning a wire between said sidewalls and on said tongues and bending said remote sidewall portions inwardly and towards said web, said wire is forced into said notches in said tongues by said wire stutfer means and an electrical connection between said wire and said connector is established.

6. A device as set forth in claim 5 wherein said wire stuifer means comprise ear means struck inwardly from said sidewalls.

-'7. A device as set forth in claim 5 wherein said wire stutfer means are provided on both of said sidewalls, and both of said sidewalls are provided with spaced-apart slots extending inwardly on each side of said stuffer means.

References Cited by the Examiner UNITED STATES PATENTS 1,936,869 11/1933 Deaver l74-88 X 2,783,447 2/1957 Watts 339-9 X FOREIGN PATENTS 607,276 3/ 1926 France.

67,278 2/ 1951 Netherlands.

25 LEWIS H. MYERS, Prmary Examiner.

D. L. CLAY, Assistant Examiner. 

5. AN ELECTRICAL CONNECTOR INTENDED TO BE APPLIED TO AN INSULATED WIRE, SAID CONNECTOR HAVING A GENERALLY CHANNELSHAPED CROSS-SECTION COMPRISING A WEB AND UPSTANDING SIDEWALLS, A PAIR OF TONGUES STRUCK-UP FROM SAID WEB AND EXTENDING TRANSVERSELY THEREACROSS, A NOTCH IN EACH OF SAID TONGUES, SAID SIDEWALLS EACH HAVING A REMOTE PORTION WHICH IS REMOTE FROM SAID WEB AND EACH HAVING AN ADJACENT PORTION WHICH IS ADJACENT TO SAID WEB, SAID REMOTE PORTIONS BEING BENDABLE RELATIVELY INWARDLY TOWARDS EACH OTHER AND TOWARDS SAID WEB, AND WIRE STUFFER MEANS EXTENDING INWARDLY FROM AT LEAST ONE OF SAID SIDEWALLS, SAID WIRE STUFFER MEANS LYING BETWEEN SAID TONGUES WHEREBY UPON POSITIONING A WIRE BETWEEN SAID SIDEWALLS AND ON SAID TONGUES AND BENDING SAID REMOTE SIDEWALL PORTIONS INWARDLY AND TOWARDS SAID WEB, SAID WIRE IS FORCED INTO SAID NOTCHES IN SAID TONGUES BY SAID WIRE STUFFER MEANS AND AN ELECTRICAL CONNECTION BETWEEN SAID WIRE AND SAID CONNECTOR IS ESTABLISHED. 